Every 2004-2007 Quest is a leak waiting to happen from that power roof. The holes in the corners plug up - you have to watch that. Also, the rubber drain tubes that go down the A-pillars plug up. Sometime you can blow them out from the top - sometimes you can't. Here's the big one: those drain tubes will kink because Nissan used generic lightweight, soft rubber tubing. It sits up there in the roof cavity and bakes, get's soft, and kinks. Solution: Open up your headliner and remove the old tubes - they run down the a-pillar and are easy to get to and just dangle down into the bottom of the car (you have to pop off a couple of panels). Go to a local BOAT supply store (maybe Lowes or Home Depot as well - I didn't check them) and get the heavier, reinforced tubing with metal inside it. These won't pinch or kink. Unplug old, plugin new, and feed down the A-pillar. I did this - that was two years ago. No issues.
Same applies to the two rear drain tubes - they are almost guaranteed to kink. Why? Once again the cheap hoses bend around two corners and kink - both of mine were kinked. They run down the pillar behind the sliding door to the bottom. Same thing - replace them both. Howeverrrrrrr, , once you pull the old ones out, you will never be able to fish the new one down the same path because the gap down in the panel on the side of the car is too small. Cheat. Don't run the tube down immediately into the rear panel at the top. Leave it outside the panel - between it and the inside plastic trim panel - until you get to the bottom. THEN route it over thru a hole into the side panel and down. It is reinforced - it will be fine between the trim panel and the metal.
Had they used reinforced tubes in the first place, most of this type of thing would never have happened.
(I can't speak for 08's-09's, but I assume they have the same issue.)